Toothbrush Head Stand: Difference between revisions

Revision as of 18:00, 27 August 2017

Topic
Tutorial
Modeling
Level
Beginner
Time to complete
Less than an hour
Authors
EmmanuelG
FreeCAD version
0.16 or greater
Example files
Thingiverse 2403310
See also
None

A daily-life problem

Electric toothbrushes rarely come with a head stand, while in a family you will often see multiple heads used with one body. Many people facing a common problem lead us to a variety of solutions, as you can see on Thingiverse (200-800 projects are related to that). Here is the first answer and how to design it.

This tutorial will take you through the steps needed to model the part shown in the image below using basic tools from the Part Design Workbench (many of the tools and capabilities are not covered).

First idea : a plate

From the start-page, select Part Design, or create a new document and select the Part Design workbench.

Create a sketch

Click on New sketch. Either from the contextual task menu at the left, or the toolbar above or from the Part Design menu at the top.

A dialog prompts you to choose the sketch orientation and provide an offset.

We will pick the XY Plane as shown in the image above (that orientation correspond to the common build plate of most 3D printers), then click OK.

You now are facing the XY plane from above, and have access to the drawing tools.

Click on Rectangle.
Place a first point.
Place the opposite corner.
Press ESC or click the right mouse button to stop using the tool.

You now have a floating rectangle of unspecified dimensions.

Click on a line of the rectangle, you now have access to the constraint tools at the right of the toolbar (depending of the size of your screen you may need to drag them to the left in order to see them all)
Click on Length
A dialog prompts you to set a dimension. Enter 80mm, click OK.
Repeat with the other side of the rectangle, also 80mm.

You now have a floating square.

Click on the lower left point of the square.
Click on the origin of the XY plane (at the intersection of the two thick lines).
Click on Coincident.

You now have a totally constrained sketch, as you are told by the solver on the left and the change of color. It is a good practice to always have a totally constrained sketch.

An under-constrained sketch can leave room for unwanted change, if you modify something later on. On the opposite, an over-constrained sketch is also not good. In that case the solver warn you of redundant constraints and you should remove some of them.

To leave the sketch, click either on the "Close" button on the left, or the icon in the toolbar, or press ESC.

You now only see the square, and the contextual task menu on the left show you more options than before.

Create a pad

Click on Axonometric among the standard views, to better see what will happen.
Click on Pad.
Enter 4mm and click OK.

Your sketch is now in volume !

Create a sketch on it

Select the upper face

The color of the face change and you have more options in the contextual task menu.

Click on New sketch. As a face was selected it will not ask you to choose a plane.

Click on Circle, place the center, then the radius.
Draw 4 circles
Press ESC or click the right mouse button to stop using the tool.

Select the circles
Click on Equal Length

Now the circles share the same radius.

Click on External geometry.
Click on the four sides of the square, it add lines, color magenta.

Theses lines will serve as reference to position the circles.

Use Length to position them at 20mm from the edges.

Click on a circle
Click on Radius and set it at 1,5mm.

To leave the sketch, click either on the "Close" button on the left, or the icon in the toolbar, or press ESC.

Create a pad

Click on Axonometric among the standard views, to better see what will happen.
Click on Pad.
Enter 25mm and click OK.

You have the basic shape, it just need final touches.

Rounding the corners

Holding CTRL click on the vertical edge at each corner to select the four of them.

Don't hesitate to help you by switching the display mode (just at the left of the Axonometric View) between Wireframe and Wireframe and shadow.

Click on Fillet.
Set the radius at 20mm.

Much better.

Making it more robust

We need to add material at the base of the cylinders to make them less prone to snap. Because of the printing orientation these small surfaces will be fragile at the junction with the base.

Select the circles at the base of the cylinders

Click on Chamfer.
Set it to 2mm.

Chamfer the edges

Select the face under the base, add a Chamfer of 0,5mm.

The first layer of plastic is often being squashed a little too much, this will compensate that and save you time in cleaning the model. If the first layer is ok that will make it only nicer

Select the edges at the border of the upper face (holding CTRL ).

Add a Chamfer of 1mm. This one is only aesthetic.

Tadaa !

Export as a .STL

In the Combo View on the left, select the tree view instead of the contextual task menu, click on the last feature (the chamfer).

Now you can select "Export..." from the File menu at the top left, and select the file format .STL.
Just print it :-)

Second idea : a band

The above model make a good starting point to use FreeCAD, but as a toothbrush head stand it have its flaws.

To be continued

Other languages:

@@ Line 123: / Line 123: @@
+* To leave the sketch, click either on the "Close" button on the left, or the [[File:Sketcher_LeaveSketch.png|32px]] icon in the toolbar, or press {{KEY|ESC}}.
-* Leave the sketch.
 [[File:TBHS-15.JPG|800px|center]]
 === Create a pad===
+* Click on [[Image:View-axometric.png|32px]] '''Axonometric''' among the standard views, to better see what will happen.
-Cylinders !
+* Click on [[File:PartDesign_Pad.png|32px]] '''Pad'''.
+* Enter 25mm and click OK.
+[[File:TBHS-16.JPG|800px|center]]
-=== Final touches ===
-Rounding the edges.
-== Second idea ==
+You have the basic shape, it just need final touches.
-=== Main part with pad ===
-Now in the Combo View, click on the OK button to leave the sketch edit mode and select [[File:PartDesign Pad.png|32px]] Pad from the toolbar or from the Part Design menu. This will give you a Pad dialog in the Combo View. Using that dialog, first using the Type pulldown menu, select Two dimensions. Drawing presented at the beginning of this tutorial says the part is 53 mm long. We do it by Padding our sketch both ways from the center plane to make up that distance i.e. make the pad symmetric in relation of sketch-plane. The reason for is seen later when creating features. For now, given we want it to be 53 mm long in total we will input 26.5 for Length, and 26.5 again for the Second length. Alternatively, you can provide a single length of 53 mm and click the Symmetric to plane check box. Once that is done we now have our base solid upon which we will add additional features to construct our part.
+=== Rounding the corners ===
+* Holding {{KEY|CTRL}} click on the vertical edge at each corner to select the four of them.
+Don't hesitate to help you by switching the display mode (just at the left of the Axonometric View) between [[File:DrawStyleWireFrame.svg|32px]] '''Wireframe''' and [[File:DrawStyleFlatLines.svg|32px]] '''Wireframe and shadow'''.
-Your model will have some extra lines on it compared to the images in this tutorial.  To remove these extra lines, change to the OpenSCAD workbench, select Pocket001 from the hierarchy tree, and click the Refine Shape tool: [[Image:OpenSCAD_RefineShapeFeature.png|32px]].  This creates a refined version of the model that is parametrically linked to Pocket001 and so is also linked to the entire history of the model.  If we change, for example, the numerical value of a distance constraint the Refined Shape will update.  In contrast, the Part WorkBench also has a Refine Shape tool in the pulldown menu, and it creates a Refined Shape that is more like a snapshot of the model as it existed when the Refine Shape tool was used.  If we change (for example again) the numerical value of a distance constraint, Refine Shape created from the Part Workbench remains the same and does not update.
+[[File:TBHS-17.JPG|800px|center]]
-This tutorial and your model are complete.
+* Click on [[File:PartDesign_Fillet.png|32px]] [[PartDesign_Fillet|'''Fillet''']].
-== Additional Resources ==
+* Set the radius at 20mm.
+[[File:TBHS-18.JPG|800px|center]]
-*Links to accompanying video have been included.
-*FreeCAD file for comparison (made with 0.16.6706) [https://github.com/FreeCAD/Examples/blob/master/Basic_Part_Design_Tutorial_Example_Files/Basic_Part_Design_Tutorial.FCStd Download]
+Much better.
+=== Making it more robust ===
+We need to add material at the base of the cylinders to make them less prone to snap. Because of the printing orientation these small surfaces will be fragile at the junction with the base.
+* Select the circles at the base of the cylinders
+[[File:TBHS-19.JPG|800px|center]]
+* Click on [[File:PartDesign_Chamfer.png|32px]] [[PartDesign_Chamfer|'''Chamfer''']].
+* Set it to 2mm.
+[[File:TBHS-20.JPG|800px|center]]
+=== Chamfer the edges ===
+* Select the face under the base, add a [[File:PartDesign_Chamfer.png|32px]] '''Chamfer''' of 0,5mm.
+The first layer of plastic is often being squashed a little too much, this will compensate that and save you time in cleaning the model. If the first layer is ok that will make it only nicer
+[[File:TBHS-21.JPG|800px|center]]
+* Select the edges at the border of the upper face (holding {{KEY|CTRL}} ).
+[[File:TBHS-23.JPG|800px|center]]
+* Add a [[File:PartDesign_Chamfer.png|32px]] '''Chamfer''' of 1mm. This one is only aesthetic.
+[[File:TBHS-22.JPG|800px|center]]
+Tadaa !
+== Export as a .STL ==
+* In the Combo View on the left, select the tree view instead of the contextual task menu, click on the last feature (the chamfer).
+[[File:TBHS-24.JPG|800px|center]]
+* Now you can select "Export..." from the File menu at the top left, and select the file format .STL.
+* Just print it :-)
+== Second idea : a band ==
+The above model make a good starting point to use FreeCAD, but as a toothbrush head stand it have its flaws.
+''To be continued''
 {{clear}}